Rising to the Challenge - Inverter Efficiency

One common misconception is assuming that the inverter's output remains constant under all operating conditions. However, just like PV panels, inverters also experience efficiency decreases in response to the temperature increases, and these impacts are projected to skyrocket due to climate change. This holds serious implications for the performance of PV systems.

Consider Victron's popular inverter, the MultiPlus-II 230V. It can produce a maximum power output of 15kVA under ideal conditions at 25°C. However, as temperatures increase, the continuous output power of the inverter decreases significantly. At 40°C, the output decreases to 10kVA, and at 65°C, it drops to just 7kVA - less than half of its full capacity.

The output power of the inverter acts as a bottleneck, regardless of the surplus energy produced by the PV panels. The energy output of the system cannot exceed the inverter's reduced capacity, leading to energy losses and a limited system performance.

For optimal performance of a PV system, it's crucial to consider several factors. Firstly, when sizing the system, it's imperative to match the capacity of the PV panels to the inverters. Additionally, the system's location and seasonal temperatures must be considered as they affect the maximum output. To mitigate the risk of underperformance, it's essential to install the inverters in shaded areas with sufficient airflow. Where this is not possible, it is recommended that mechanical cooling be installed. Thus, by accurately matching the inverter's capacity to the expected operating conditions, we can ensure that the system operates efficiently year-round.